Larger power dissipations in the central processing modules (CPU) used in consumer and desktop computer systems are requiring cooling systems of greater capacity than previously used in the industry. These are more massive, and by their greater mass, create new mechanical problems. As microprocessors have become more powerful and more compact, there has been a need to ensure that an efficient cooling system be in place to allow for the proper operation of the computer. Desktop computer systems are utilized in professional environments, educational environments and at home. As is well known these computers can be networked or they can be standalone devices.
Standard practice within the computer industry is to mount heatsink assemblies to the printed circuit board that contains the electronic components to be cooled. With relatively smaller cooling systems, this can be implemented as a simple direct assembly. As microprocessors become smaller and more powerful they generate more heat. For example, microprocessors used in conventional systems dissipate between 20–60 watts of power whereas the more powerful systems will dissipate over 100 watts of power.
With these higher performance systems, the large mass of the cooling system can create excessive stresses on the printed circuit boards when subjected to shock and vibration loads. Furthermore, as the microprocessor becomes smaller the heat flux density is greater, the resistance to conduction is greater, and therefore the size of the heat sink must be greater to ensure that the heat is dissipated. This further exacerbates the loading and vibrational problems when using conventional heat sink assemblies when attempting to keep the computer system cool.
A conventional way to provide a cooling system in a computer system is to mount the heatsink via a spring loaded compression system. FIG. 1 is a partial cutaway view of the interior of a computer assembly 10 which includes a conventional system for cooling a microprocessor within the computer assembly. The computer assembly 10 includes a chassis 12. A circuit board 14 is coupled rigidly to the chassis to ensure that it has the proper orientation. A heat sink 16 is coupled to the board via spring 20 in compression to provide cooling to the microprocessor 18 on the circuit board 14. This creates a vulnerability to dislocation of the thermal interface when shocked or vibrated, as the suspended heatsink mass is free to move, influenced only by the compliant springs.
In some conventional computer assemblies, the processor is mounted on a separate dedicated printed circuit board (i.e., a daughter board), rather than following the common industry practice of installing it on the main logic board. The daughter board is fastened to the logic board, allowing the entire cooling system and daughter card to be cantilevered from the logic board. This also makes the computer system more vulnerable to damage by shock and vibration loading when a large heat sink is utilized.
Finally, systems with daughter cards or socketed processors typically use high density signal connectors with very limited engagement range. Such systems are vulnerable to disconnection or improper connection if the positions of the related printed circuit boards vary. The connectors are also highly fragile, and are easily damaged in installation or field repair service.
Accordingly, what is needed is a system and method for overcoming the above-identified problems. The present invention addresses such a need.